@CollectionSize.Require(ZERO)
  public void testIsEmpty_yes() {
    assertTrue("isEmpty() should return true", collection.isEmpty());
  }

  @CollectionSize.Require(absent = ZERO)
  public void testIsEmpty_no() {
    assertFalse("isEmpty() should return false", collection.isEmpty());
  }

     * Test method for
     * {@link org.codelibs.core.collection.CollectionsUtil#isEmpty(java.util.Collection)}
     * .
     */
    @Test
    public void testIsEmptyCollectionOfQ() {
        Collection<String> c = null;
        assertThat(CollectionsUtil.isEmpty(c), is(true));
        c = new ArrayList<String>();
        assertThat(CollectionsUtil.isEmpty(c), is(true));
    }

    /**
     * Test method for

        if (!requiredSelectors.isEmpty() || !optionalSelectors.isEmpty()) {
            Set<MavenProject> selectedProjects =
                    projectSelector.getActiveProjects(request, allSortedProjects, projectActivation.getActivations());

            // it can be empty when an optional project is missing from the reactor, fallback to returning all projects
            if (!selectedProjects.isEmpty()) {

        if (excludes == null || excludes.isEmpty()) {
            return Collections.emptyList();
        }
        return Arrays.stream(excludes.split(","))
                .map(String::trim)
                .filter(s -> !s.isEmpty())
                .collect(Collectors.toList());
    }

    public boolean isEmpty() {
        return entry == null || vertices == null || vertices.isEmpty();
    }

    // ------------------------------------------------------------------------
    public boolean isEmptyEdges() {
        return isEmpty() || incidentEdges == null || incidentEdges.isEmpty();
    }

  @CollectionSize.Require(ZERO)
  public void testIsEmpty_yes() {
    assertTrue("isEmpty() should return true", getMap().isEmpty());
  }

  @CollectionSize.Require(absent = ZERO)
  public void testIsEmpty_no() {
    assertFalse("isEmpty() should return false", getMap().isEmpty());
  }

    assertThat(requirements.getPresentFeatures()).isEmpty();
    assertThat(requirements.getAbsentFeatures()).isEmpty();
  }

  public void testBuildTesterRequirements_class_empty() throws Exception {
    @Require
    class Tester {}

    TesterRequirements requirements = buildTesterRequirements(Tester.class);

    assertThat(requirements.getPresentFeatures()).isEmpty();

    assertEquals(rangeSet.asRanges().isEmpty(), rangeSet.isEmpty());
    assertEquals(rangeSet.asDescendingSetOfRanges().isEmpty(), rangeSet.isEmpty());
    assertEquals(!rangeSet.asRanges().iterator().hasNext(), rangeSet.isEmpty());
    assertEquals(!rangeSet.asDescendingSetOfRanges().iterator().hasNext(), rangeSet.isEmpty());

    List<Range<C>> asRanges = ImmutableList.copyOf(rangeSet.asRanges());

        if (context.options().alsoMake().isPresent()
                && context.options().alsoMakeDependents().isEmpty()) {
            return MavenExecutionRequest.REACTOR_MAKE_UPSTREAM;
        } else if (context.options().alsoMake().isEmpty()
                && context.options().alsoMakeDependents().isPresent()) {
            return MavenExecutionRequest.REACTOR_MAKE_DOWNSTREAM;

        Set<Artifact> resolved = new LinkedHashSet<>();

        if (projects == null || projects.isEmpty()) {
            return resolved;
        }

        if ((scopesToCollect == null || scopesToCollect.isEmpty())
                && (scopesToResolve == null || scopesToResolve.isEmpty())) {
            return resolved;
        }

        /*

        Logic for transitive global exclusions